The present invention relates to an improved belt core. For shipping purposes, heavy belting must be rolled up on a core device which is customarily made from metal or wood or in some cases sawdust combined with epoxy resins. Experience with rolling up of heavy belting on cores has revealed that since many types of belting are heavy, wood is not a strong enough material for use in making a core. Furthermore, wood is quite expensive and must be fabricated into a shape which will accomodate the roll of belt, therefore, usually a wooden box that will accomodate the square shaft of the windup machine is fabricated of sufficient length to extend to the laterial sides of the rolled up belt, or otherwise, wooden belt cores are cut from lumber and are formed with a non-circular hole in the middle thereof which may be lined up with the correspondingly configured shaft with as many cores being used as are necessary to handle the anticipated weight of the roll.
In most instances, when metal has been used to manufacture the core, the core generally comprises a piece of pipe which is cut to the appropriate length, has a non-ciruclar hole therethrough formed by adapter plates welded into each end and each having the hole therethrough, and further including a slot usually torched into the side of the pipe so as to enable the tucking of the end of the belt therein to start the roll. Metal cores made in this fashion are extremely expensive due to the large expense of pipes of that size, and in view of the labor involved in torching the slot and welding the adapter plates, the use of a metal pipe in this fashion is not practical.
As stated above, another material which may be utilized in making a core is sawdust which has been combined with epoxy resins and cast into the core in continuous lengths up to, for example, six feet long, and including a non-circular hole therethrough. When sawdust cores are used, the belt end is attached to the core by nails or other means and then the belt is wound up thereon. As is the case with the metallic pipe described above, cores made of the sawdust-epoxy resin combination are expensive and have also been found to be brittle. Because of this brittleness, sawdust-epoxy resin cores tend to break up when the belt ends are attached thereto by nailing, so they are generally not usable and furthermore due to the nature of the epoxy resin material, these cores are difficult to cut to the desired length.
The following prior art references are known to Applicant:
U.S. Pat. No. 355,145 to Davis, et al. teaches the concept of a core device having a square opening therethrough for winding purposes. This patent is believed to be of only general interest concerning the teachings of the present invention since, of course, the present invention may utilize an opening therethrough of any shape which is compatible with a device for winding the core and the belt attached thereto.
Each of U.S. Pat. Nos. 730,239 to Davis and 1,147,875 to Connerman teaches a core device having a retention member including a plurality of teeth which enhance the retention thereof. The present invention is distinct from each of these patents since in each of these patents, the teeth are on moving members which rely upon mechanical activation to lock the belt end therein. In the present invention, the teeth which are used are passive and require no mechanical mechanism, but rather rely upon the tension of the winding procedure to make the teeth grip the belt end.
U.S. Pat. No. 3,361,380 to Mizutani discloses a spool for photographic film which includes a recess having teeth therein for retention purposes. The present invention differs from the teachings of Mizutani since, in fact, the teeth thereof are really hooks which are utilized to engage pre-formed holes in the end of the film so as to retain the film thereon. In the present invention, no end preparation of the material which is being rolled up is required.
U.S. Pat. No. 3,782,651 to Henglehaupt discloses a spool having a curved groove which is utilized to carry a ribbon from one location to another. Since the curved groove does not perform the retention functions performed by the recess of the present invention, this patent is believed to be of only general interest concerning the teachings of the present invention.
U.S. Pat. No. 4,266,738 to Nakagawa discloses a tape reel having a recess formed by a pivotal member including interengagable teeth which are utilized to retain the tape therein. This device is similar to Davis and Connerman discussed above since the Nakagawa device uses a movable member including teeth whereas in the present invention the teeth are completely passive and stationary.
U.S. Pat. Nos. 3,620,469 to Riedel, et al. and 4,436,253 to Watanabe each disclose a reel having a peripheral recess into which may be frictionally retained a plug member so as to enable the retention therein of the material which is to be wound up on the reel. This is believed different from the teachings of the present invention since in the present invention the peripheral recesses which are disclosed are utilized so as to enable the insertion therein of standard size wood pieces onto which the belt end may be attached.
Accordingly, a need has developed for a simple belt core device which is cheap enough to manufacture so that it may be disposable, that is, the shipper of belt products who provides the belt cores need not worry about charging the customer for the cores or about the expense of having the cores returned. In this light, and in order to overcome all of the deficiencies of the prior art as set forth above, the present invention was developed.